Depressão por endogamia em populações de jequitibá-rosa

Abstract

This research studies the inbreeding effects on three populations of jequitibá-rosa - Cariniana legalis (Mart.) O. Ktze., with 17 years old of experimentation, planted in two localities of São Paulo State. The assay was implanted in 1982, in compact family block design with the purpose of ex situ conservation. One third of alI individuais was measured for quantitative traits, stem shape, DBH, height and wood volume and using 14 polymorphic isozymes loci. The individuais of each population were grouped in five classes based on diameter and they were estimated by their respective phenotypic average of the traits, observed heterozygosity and fixation index. The analysis of linear regression among traits and index of diversity, showed the tendency in increasing in grown with increásing of heterozygosity and reduction of the inbreeding, suggesting that it is happening selection in favor to heterozygous. However, the analysis of genetic divergence among alIelic frequencies of each group, has indicated with the detected inbreeding is fúnction of the mating system a!1d. not of the selection, suggesting that the individuals of smaller performance should be the result of the inbreeding effects. The quantification : of inbreeding effects showed 20%, 68%, 63% and 90% to stem shape, DBH, height and wood volume, respectively. They were also appraised the implications of those results for ex situ conservation and for the genetic improvement.